Conventionally, as a mechanical type drive source generally used, there has been a motor, a hydraulic or pneumatic type actuator or the like, but many of them are generally composed of metal and require large mass and space, and in addition, a lot of energy as a necessary drive source.
In addition, EP-A-1550689 discloses an actuator using an organic material which is obtainable in lightweight and in a space-saving way. A conductive polymer used here aims at utilization of electrochemical redox reaction, and application of expansion and contraction of the organic material to the above problems. However, a specific shape example obtained is limited to a film-like shape, and an expansion and contraction direction is also limited to one example of a longitudinal direction, and it is a type without accompanying volume change.
Furthermore, WO2004054082 describes a combination of a gel and a solvent as an example of one showing volume change. However, since it derives deformation of a skeleton material by squeezing out the solvent from the skeleton formed by gel with the use of electric stimulus, deformation speed is very moderate. Since it aims at driving a gel actuator, which was originally driving in a solvent, in air, it requires to have a solvent tank as a system, and thus has high risk of generating leakage of an electrolyte solution, or performance deterioration caused by electrolysis.